Nutella Per Minute

    @stdlib/utils-try-then
    TypeScript icon, indicating that this package has built-in type declarations

    0.0.7 • Public • Published

    trythen

    NPM version Build Status Coverage Status

    If a function does not throw, return the function return value; otherwise, return the return value of a second function.

    Installation

    npm install @stdlib/utils-try-then

    Usage

    var trythen = require( '@stdlib/utils-try-then' );

    trythen( x, y )

    If a function x does not throw, returns the return value of x; otherwise, returns the return value of a second function y.

    function x1() {
        return 1.0;
    }
    
    function x2() {
        throw new Error( 'beep' );
    }
    
    function y() {
        return -1.0;
    }
    
    var z = trythen( x1, y );
    // returns 1.0
    
    z = trythen( x2, y );
    // returns -1.0

    The function y is provided a single argument:

    • error: the error thrown by x
    var randu = require( '@stdlib/random-base-randu' );
    
    function x() {
        if ( randu() < 0.5 ) {
            throw new Error( 'beep' );
        }
        throw new TypeError( 'boop' );
    }
    
    function y( err ) {
        if ( err instanceof TypeError ) {
            return 'boops';
        }
        return 'beeps';
    }
    
    var z = trythen( x, y );
    // returns <string>

    Examples

    var randu = require( '@stdlib/random-base-randu' );
    var ceil = require( '@stdlib/math-base-special-ceil' );
    var repeatString = require( '@stdlib/string-repeat' );
    var trythen = require( '@stdlib/utils-try-then' );
    
    var z;
    var i;
    
    function x() {
        if ( randu() < 0.9 ) {
            throw new Error( 'BOOP' );
        }
        return repeatString( 'BOOP', ceil( randu()*3.0 ) );
    }
    
    function y() {
        return repeatString( 'beep', ceil( randu()*5.0 ) );
    }
    
    for ( i = 0; i < 100; i++ ) {
        z = trythen( x, y );
        console.log( z );
    }

    See Also

    • @stdlib/utils/try-catch: if a function does not throw, return the function return value; otherwise, return y.
    • @stdlib/utils/async/try-then: if a function does not return an error, invoke a callback with the function result; otherwise, invoke a second function.

    Notice

    This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

    For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.

    Community

    Chat


    License

    See LICENSE.

    Copyright

    Copyright © 2016-2022. The Stdlib Authors.

    Install

    npm i @stdlib/utils-try-then

    Homepage

    stdlib.io

    DownloadsWeekly Downloads

    19

    Version

    0.0.7

    License

    Apache-2.0

    Unpacked Size

    40.3 kB

    Total Files

    9

    Last publish

    Collaborators

    • stdlib-bot
    • kgryte
    • planeshifter
    • rreusser